ERIC Alexander is being very naive (BFP 6th) if he bases his knowledge of climate change on a science fiction film made by a failed US vice president, television programmes whose contents have been faked and a politician having his photo taken standing at the North Pole.

Roderick Taylor’s letter rightly highlights the large changes that have occurred in the global climate irrespective of the alarmists believe that it is all due to manmade causes.

It was the Serbian Engineer and Mathematician Milutin Milankovitch who in 1938 hypothesised that the earth’s orbit around the sun is constantly changing. It was these orbital variations caused largely by the gravitational pull of Jupiter and Venus that result in ice ages occurring about every 90,000 years with an interglacial warm period of about 10,000 years. Today we are living near the end of the most recent interglacial period.

Ice cores taken from the Greenland ice cap show a close correlation with Milankovitch theory and show there has been a succession of Ice Ages in the past 800,000 years. Evidence also suggests that increases of CO2 have been the result of global warming and not the cause, as the warmists would have us believe. Greenhouse gases are essential to life on earth without which the UK would be buried under several hundred meters of ice.

It is the very serious consequences of global cooling that should occupy our minds. A fact that I have highlighted in many of my previous letters.

As the earth cools at the start of the next ice age, permanent ice sheets will spread down from the pole.

It is likely the northern hemisphere will be buried in permanent ice hundreds of feet thick that will last for another 90,000 years.

The renewal of ice age conditions will render a large fraction of the world’s food growing area inoperable and would eventually lead to an extinction of most of the global human population It is worth remembering that virtually all the progress in human civilisation has happened during the current interglacial period. The big question remains, what will happen to human civilisation once the next Ice Age arrives?

Anthony Weeden, Bockmer End, Nr Marlow